Should You Think Twice About That Second Cup of Coffee?

Research published in December 2022 in the Journal of the American Heart Association, found that drinking two or more cups of coffee a day may double the risk of death from cardiovascular disease among people with severe high blood pressure (160/100 mm Hg or higher).

According to the Center for Disease Control (CDC), blood pressure is the pressure of blood pushing against the walls of your arteries. Arteries carry blood from your heart to other parts of your body. Your blood pressure normally rises and falls throughout the day. Having blood pressure that measures consistently above normal may result in a diagnosis of high blood pressure, or hypertension. The higher your blood pressure levels, the more risk you have for other health problems such as heart disease, heart attacks, and stroke.

There are two types of hypertension: primary, which can develop for no identifiable reason; and secondary, which develops as a result of an underlying condition or disease such as kidney disease, adrenal disease, thyroid disease and sleep apnea.

To decrease the risk of hypertension, the CDC recommends a healthy lifestyle including a healthy diet, exercise, maintaining a healthy weight, not smoking, managing stress and getting proper amounts of sleep.. 

So, if you have severe high blood pressure, should you immediately pass on the coffee refill? Before drawing any definite conclusions and providing an absolute answer to this question, Cardiologist Gene Iucci, DO, FACC, with Penn Cardiology-Somers Point recommends taking a closer look at the survey method and research sample used in this study.

"This study was an interesting read, and from a physician standpoint, the researchers discovered some good, and unfortunately not so good, findings," said Dr. Iucci. "When looking at the data from a cardiologist's point of view, there are a few elements of how the study was conducted that prevent any absolute conclusion from being drawn for patients in our region. For example, the study was conducted exclusively in Japan, where things that affect heart health, like diet, lifestyle, and habits, are generally much different than in Southern New Jersey.”

It’s also important to note the study of 18,600 people showed that for people with high blood pressure, but not high enough to be considered severe, coffee doesn’t double the risk of death from cardiovascular disease. The study also found that drinking only one cup of coffee a day was not associated with an increased risk of death from cardiovascular disease at any blood pressure level. In contrast, drinking green tea was not associated with an increased risk of death related to cardiovascular disease at any blood pressure level, although both coffee and tea contain caffeine.

"I also prefer studies that are 'double-blinded,' meaning that they have a control mechanism in place, such as the use of a placebo," continued Dr. Iucci. "This study did not have that control mechanism and was conducted by observation research which relied on the participants to provide information on their own. And, it does not address the fact that those with severe hypertension have a higher cardiovascular mortality even if they are not a coffee drinker. The study also did not specify if the coffee consumed was caffeinated or decaffeinated."

While each patient is different, Dr. Iucci does recommend curtailing or eliminating caffeine consumption if a person is experiencing palpitations soon after digestion. He recommends that patients who have arrhythmias (irregular heartbeat) and tachyarrhythmias (abnormal heart rhythms) should also alter their lifestyles and diets.

"In general, I do not discourage my patients from drinking coffee," said Dr. Iucci. “But, I do recommend consuming caffeinated drinks in moderation, and recommend low sugar drinks, seltzers and water with squeezed lemon to stay hydrated."